.header {
    width: 100%;
    height: 5rem;
    background-color: #12dbff;
    position: fixed;
    top: 0;
    box-shadow: 4px 0 5px 1px #000;
    z-index: 5;
}

/* 显示导航栏部分 */
.show-nav {
    width: 12rem;
}

.show-nav ul {
    width: 75%;
    margin: 0 auto;
}

.show-nav ul li {
    width: 2rem;
}

.show-nav ul li a {
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    border-bottom: 2px solid transparent;
    padding-bottom: 5px;
}

.show-nav ul li a:hover {
    border-bottom: 2px solid #fff;
}

/* 隐藏显示导航栏盒子 */
.box-line {
    width: 30px;
    height: 24px;
    cursor: pointer;
    line-height: 30px;
    display: none;
}

.box-line .line {
    width: 100%;
    height: 2px;
    background-color: #666;
}

.box-line .line:nth-child(2) {
    margin: 9px 0;
}

.hidde-nav {
    width: 15rem;
    height: 12rem;
    background-color: #fff;
    position: fixed;
    top: -100%;
    left: 50%;
    transform: translate(-50%, 0);
}

.hidde-nav ul {
    width: 100%;
    height: 100%;
}

.hidde-nav ul li {
    text-align: center;
    width: 100%;
    height: 4rem;
    cursor: pointer;
}

.hidde-nav ul li a {
    line-height: 4rem;
    color: brown;
}

.hidde-nav ul li:hover {
    background-color: #efefef;
}